ellerbeck



Dec. 1, 1964 G. c. ELLERBECK 3,159,341

EXTENDED SQUARE ROOT MECHANISM FOR A SQUARE ROOT CALCULATING MACHINE IIII Dec. 1, 1964 G. c. ELLERBECK `Ex'marmn SQUARE RooT MRcHANIsM FoR A SQUARE RooT CALCULATING MACHINE 5 Sheets-Sheet 2 Filed Feb. 14, 1965 Dec. 1, 1964 G. c. ELLERBECK 3,159,341

EXTENDED SQUARE ROOT MECHANISM FOR A SQUARE Filed Feb. 14, 1965 3,1 assi a sults in the subtraction of the value of 5 in the predetermined order in the first cycle of operation, and in each successive cycle the value is increased by l (or 1 in the next higher order) until the operation causes an overdraft. Thereupon, the overdraft is automatically corrected and the carriage is shifted one order to the left. Substantially simultaneously with the shifting of the carriage, the is erased and inserted in the next lower order, the value standing in the tens order of the previous series of the divisor remaining unchanged. In the first cycle of operation after the carriage is shifted, the value standing in the tens order of the divisor at the time of the overdraft constitutes the value standing in the hundreds order, the first cycle subtracting that value plus 05. Each successive cycle progressively changes this value by increasing it by 10, so that the second cycle will have standing in the lower orders of the divisor, the hundreds value remaining unchanged. This second series of operations is continued to an overdraft, after which the overdraft is corrected and the carriage again shifts to the left, and the operation repeated.

I. GENERAL DESCRIPTION Without reference to the drawings it will be understood that the machine in which the present invention is embodied is provided with the usual mechanisms, such as the selection mechanism, the accumulator, a tens-transfer mechanism, means for effecting the shifting of the accumulator in either direction, and means for automatically dividing a dividend by a divisor. Because the abovementioned components are old per se, it is believed unnecessary to describe them herein, and for a full and complete description thereof, reference may be made to either of the above-mentioned patents.

n. SQUARE noor MECHANISM (a) Genera! At the beginning of this disclosure it was mentioned that the present machine is similar to that disclosed in my patent, No. 2,736,494, so the basic mechanism will not be described herein. It will be assumed that operation will be initiated by depression of an initiating key, that opertion of such a key Will automatically shift the accumulator carriage to the proper ordinal position, and the radicand inserted tive times in the accumulator.

It can be noted, however, that in my present machine the carriage is automatically shifted in the highest ordinal position (the twelfth, in this case, as contrasted to the tenth in my prior patent) when there is an even number of whole digits in the radicand, or in the adjacent ordinal position when there is an odd number of whole digits in the radicand; and that after the entry of the radicand, an additional shift is attempted which is ineffective if the carriage is already in that position, i.e., if there is an even number of whole digits in the radicand.

(b) Square Root .Programng Mechanism (FIGS. 1, 3 to 6) As mentioned in my earlier patent, means is provided for blocking operation of the square root programing mechanism until the register carriage is in its extreme right-hand position, in those cases where a shift occurs after entry of the radicand factor. rthis blocking means is under control of a delay latch shown particularly in FIG. of Patent No. 2,736,494 and is effective to control operation of the square root control shaft Z@ (see FIGS. l, 5 and 6). As explained in the above-mentioned patent, the control shaft 24B is first rocked clockwise, as viewed in FIGS. 5 and 6, and thereafter latched in that position by the delay latch for the machine cycles required for entering the radicand five times into the accumulator. During the next-to-the-last of the entry cycles the division mechanism is set for operation by the abovementioned means, but actual initiation of division is prevented until the start of the next cycle. The delay latch is released at approximately the point in this iinal entry cycle which, in turn, releases the shaft 20 and the mechanism controlled thereby, as will be described hereinafter. During the last cycle of this programed entry operation, the conventional division aligner mechanism is conditioned to shift the register carriage to its extreme right-hand position, if not already there. If the carriage is already in its extreme position, the 'aligner mechanism starts the first of three idle aligning cycles to release and enable the usual carriage shift mechanism. Thus, in the last entry cycle, the shaft 2@ is rocked sharply counterclockwise by means of a strong spring (not shown) to its normal, or home position. The rocking of the shaft 26, as it is restored to its normal position, operates a mechanism for controlling the square root programing mechanism. This control mechanism comprises two arms: The first arm 21 (FIG. 5) causes a shifting of the square root cam shaft (of the selection programing mechanism) into operative position if the carriage is in its extreme right-hand position, and conditions a mechanism for such shifting as soon as the carriage is in its extreme position, if the entry of the radicand factor occurred in the next to the last carriage position; and the second arm 4l (FG. 6) operates a mechanism which inserts a value of 5 in the eleventh order of the keyboard, thereby providing the iirst subtraction of 5 in the first digitation cycle as is required to carry out the program of square root extraction.

(l) Cam shaft szifz.-The iirst mentioned of these mechanisms comprises the arm 21 (see particularly FiG. 5) depending from, and rigidly fixed to, the control shaft 2h. Rockably mounted on the lower end of the arm 21 is a pusher arm 22, which is urged upwardly by a suitable spring 23 tensioned between the two arms. The pusher arm 22 extends rearwardly (to the right in FIG. 5) and at its rearward end is provided with a suitable latching shoulder 24 adapted to engage and operate a cam shaft shift lever 25 (see also FIGS. 1 and 4). This lever 25 is rocked, as will be explained hereinafter, if the program mechanism has been operated through tive machine cycles, and a division operation has been initiated. The pusher arm 22 is also provided with a stud 26 for rendering the arm 22 inoperative in all operations except division. The desired control for rendering arm 22 inoperative in all operations of the machine except division is preferably secured by means of a long link 27. This link 27 is the same as link 9115 shown in FIG. 40 of my patent, No. 2,736,494, and is urged upwardly by means controlled by the division mechanism, as described in that patent. An ear 28 at the upper end of link 27 overlies and engages the stud 26. The division shaft, as pointed out in the above-mentioned patent, is rocked at the very outset of a division operation and causes upward movement of link Z7. if shaft 2h has been rocked (clockwise in FIG. 5), upward movement of link 27 permits the pusher arm 22 to rise and engage the lever Z5. t can be seen that unless the control shaft 2@ is rocked clockwise, the upward movement of link 27 is ineffective to cause the pusher arm 22 to engage the lever 25 and shift the square root cam shaft into operative position. The pusher 22 is effective to rock the cam shaft shifting lever 25 only if the machine is conditioned for square root extraction by rocking of shaft 2t) and a division operation has been initiated to lift link 27, as explained in the above-mentioned patent. However, the arm 22 is effective to rock the cam shaft shifting lever 25 when the above two preceding conditions are present.

The cam shifting lever 25 (best shown in FIG. 4) is journalled on a rivet 33 mounted in a bracket 3l extending laterally from a frame plate 32.. Associated with the lever 2S is a cam shaft shifting arm 34, likewise liournalled on the rivet 33. This second arm 34 is resiliently biased to follow the rocking of the lever 25 by a suitable spring 35 tensioned vbetween an ear on lever 25 and an ear on the arm 34. The arm 34 also carries a pin 36 which bears against the left side of a collar 37 (FIGS. 1 and 6) fixed on a square root cam shaft 38. lf the square root cam shaft 38 is in proper angular position for extraction of square root (which is dependent upon the carriage being in the extreme right-hand position as will be explained hereinafter), rocking of lever (clockwise in FIG. 4) will rock arm 34 to shift the cam shaft 38 to the right, or to its operative position for the extraction of square root. However, if the carriage is not in the proper position, i.e., in its next to extreme position, the lever 25 will rock and will be held in its rocked position by the shoulder 24. However, the square root cam shaft 38 is blocked against rightward shifting, by means explained in the next section, until the carriage is in its extreme position. Thus arm 22 is locked in its effective position, and spring yields, until the carriage is shifted to its extreme position. Thereupon, the second arm 34, under the urgency of the spring 35, will be effective to translate the cam shaft 3S to the right to control the extraction of square root.

Upon return of the division control mechanism to its normal condition, as mentioned in my prior patent', the link 27 and hence arm 2.2.) is pulled downwardly, whereupon the lever 25 is released from the shoulder 2 4 and will return to its normal position under force of the spring y35 and a spring 39 (FIG. 2) which normally urges the square root cam shaft 38 to theleft.

(2) 5s entry, adjacent highest order of keyboard (FIGS. 2, 3 and 6).-The counter-clockwise rocking of the shaft 2l), in the first cycle after initiation of division, is also effective to set a value of 5 in the next to the highest order of the selection mechanism. In the con- ,ventional ten-order machine, the 5s entry was made in the ninth order of the keyboard but, in the machine of thel present invention the "5s entry for the first ordinal operation is made in the eleventh order of the keyboard. The arm 41 is pinned on, or otherwise rigidly affixed to, the shaft 20. A pusher link 42 is journalled to the lower end of the arm 41 and, as best shown in FlG. 6, extends rearwardly adjacent the cam shaft 3S and a gear-engaging shaft 46. A suitable spring 44 is tensioned between the two arms 4l and 42 and urges the link 42 upwardly, or counter-clockwise in FIG. 6. The rearward end of the pusher link 42 is provided with two lingers. The upper linger is provided with a cam edge 43 adapted to be engaged by the conical face of the collar 3'7 on the square root cam shaft 38 so that the arm 42 will be rocked downwardly to disable the arm by the rightward movement of cam shaft 33. The other finger of the link 42 is notched to engage a pin 44 carried by an arm k 45 rigidly mounted on the gear-engaging shaft 46. Normally the lower end of the link 41 will lie below the pin k44, as seen in FIG. 6. However, when the shaft Ztl is rocked clockwise during the ve additive cycles previously mentioned, the link 42 Will be pulled to the left, and the spring 43 will lift it until the notch in the end thereof engages the pin 44. At the end .of the tive additive cycles, the keyboard will be cleared of the radicand; in the next, or sixth, cycle, the division mechanism will be tripped to initiate operation of the division control mechanism, as explained in my earlier patent; and in the seventh cycle, the shaft 20 will be released for counterclockwise movement, whereupon the link 4Z rocksy arm 45 and shaft 46 clockwise in FlG. 6. lf the carriage is in the extreme right-hand position, the cam shaft 3e will be shifted to the right, immediately following the translationof the link 42 and rocking of shaft 46. Translation of the cam shaft 3S to the right cause the conical face on they collar 37 to engage the cam face 43 of link 42 and cam it downwardly (clockwise in FlG-6) to disengage the notch from the pin 44, thereby releasing the control shaft 46 from the link. lf, on the other hand, the

`carriage is in the next to the extreme position, the cam kshaft 38 and the collar 37 cannot be translated to the right until the carriage has reached the extreme right-hand position, whereupon the link 42 will be cammed downwardly.

It should be mentioned at this point that the square root cam shaft 3S cannot be shifted to the right until the carriage is in its yextreme right-hand position and the gear-engaging arm of the highest order positioning mechanism (to be mentioned hereinafter in the section entitled Cam shaft and drive) is rocked to operative position by link 42, arm 45 and shaft 46. In every car'- riage position, one of the cams 5th will engage the `side of the associated gear-engaging arm '70, thereby preventing shifting of the shaft 46 until the arm of that order is rocked out of the way. ln the highest order, and in that order only, is means provided (i.e., link 42) for rocking the gear-engaging arm out of the way. Also, it can be noted that the rocking of the shaft 46 is operative to rock lthe highest order gear-engaging armto insert the value of 5 in the next lower order of the yselection mechanism. rlhe highest order gear-engaging arm is held in its operative position by the corresponding cam on the square root n,

cam shaft 38, and is so held until the carriage shifts from the extreme position at the termination of the first ordinal series of operations in the extraction of square root.

(c) Sql/.are Root Selection Mechanism The earn vshaft 3S (as in my prior patent) is normally biased to the left, as shown in FIG. 2, by the spring 39 encircling the shaft and seated between the end plate 49 of the square root control box and the previously mentioned collar 37. However, when the cam shaft shift arm. 34 is rocked (clockwise in FIGS. 1 and 4), the pin 36 will force the shaft 3S to the right to place a plurality of square root cams 50-1 to Sil-12, inclusive (reading right to left in PEG. l), carried thereby in operative alignment with the plurality of gear-engaging arms 7d.

(l) Cam shaft and drive (FIGS. 1, 3, 5 and 7).- Square root cam shaft 38 carries a plurality of square root cams gti-1 to 56E-l2, one in each order of the square root selection mechanism (see FIGS. l, 2 and 7). The cams Sil-3 to Sil-l2 are identical in shape, and each is provided with a single tooth 52. These cams are so arranged on the shaft 33 that each tooth is spaced at an angle of 36 from the next tooth. Thus, the cam teeth 52 are arranged spirally around the shaft, separated from each other by an. angle of 36, so that in the highest ten orders, only one square root cam 50-3 to Sil-12 vtll engage a pressure face of the associated gear-engaging arm at any time. After the cam shaft 33 has been shifted to the right, it is rotated, or fed, to rock the respective ordinal cams 5ft-3 to Sil-12 into operative position, in sequencey as the carriage is shifted toward the left during square root extraction. That is, the cam shaft 3S is rotated an additional increment of 36 as the carriage shifts from one ordinal position to another, so that the respective gear-engaging arms (starting with the highest,

`or lefthand, order and progressing to the lowest, or rightharid order, in successive ordinal steps) become opera tivein sequence. By this means the control mechanism is enabled to select the orders in which the selection mechanism is to be adjusted.

The earn shaft 3f, is driven by a stub shaft 53 (see FlGS. 1 and 5) journalled in a bracket 54 suitably supported on an auxiliary crossfrarne member`47 of the machine. The stub shaft 53 is connectedfto the cam shaft 3 by a suitable separable coupling and slip clutch device S5 which will permit the shaft 38 to beshifted to the right, and in the eventk of jamming of the mechanism, to permit relative rotation between the two plates ofthe coupling 55. f

The stub shaft 53 is driven directly from thek shifting of the carriage, whereby the stub and cam shaftsr always have an angular position determined bythe lateral position of the carriage. The mechanism forsecuring `this rotation ofthe stub shaft and cam shaft is shown particularly in FIGS. l and 5. The front carriage frame, or

7 rail, 56 is provided with a plurality of rack teeth S7 on the left-hand portion thereof. The rack teeth 57 are constantly in mesh with a pinion S which is rigidly fastened to a longitudinal shaft S9. This shaft 59 is supported in two arms of the bracket member 54 (see FIG. 5. A worm gear 60 is also rigidly journalled on the pinion shaft 59, and this worm 66 drives a gear 61 mounted on the stub shaft 53. Thus, the stub shaft S3, and through it, the cam shaft 3S, are rotated with each ordinal shift of the carriage. As mentioned in my earlier patent, the gear train is so designed and constructed as to rotate the cam shaft 38 through an angle of 36 for each ordinal shift of the carriage.

It will be recalled that in my previous patent, No. 2,736,494, the carriage was free to shift through nine ordinal steps of movement. However, in the preferred form of my present invention, the shifting of the carriage is extended to eleven ordinal steps of movement (i.e., to twelve ordinal positions), whereby the extraction of square root is extended two orders. Thus, when the cam shaft 38 is rotated 36 for each ordinal step of movement of the carriage, the cam shaft, and the cams mo-unted thereon, will have a differential angular position for each ordinal position of the carriage. It might appear that this 36 rotation of the cams would cause an interference between the two highest order cams and the two lowest order earns. This would be true, except for the novel mechanism of the present invention, as will be described in detail hereinafter.

(2) Gear-engaging arms (FIGS. 2 and 7).-n each order of the square root programing mechanism, gearengaging arms 7G are ordinally positioned against a plurality of ordinally arranged separator plates, as fully shown and described in the above-noted patent. ln all orders of the square root mechanism, the gear-engaging arms 'i9 are identical in shape and size, are rockably journalled on the long shaft 46 previously mentioned (except the highest order arm as will be mentioned later), and are rocked by the single tooth 52 on the associated cam Stb-1 to Sti-lll. The square root cams it-li and 5ft-2, associated with the first and second orders of the machine, are slidably but nonrotatably mounted on a square portion of the cam shaft 33 for preventing operation of cams Sti-2 or Sti-1 at the same time that cams Sti-12 or Sti-il are operated, as will be described hereinafter. In the twelfth, or highest, order the gear-engaging arm 7? is pinned, 0r otherwise rigidly affixed, to the shaft 46, so that it will be rocked with the rocking of the shaft from operation of arm 42 (FlG. 6) described above. When so rocked, the pressure face 71 will be rocked away from the tooth 52 on the coordinal cam StD-i2, and shaft 3S can shift to the right. Thereupon, tooth 52 of the cam 5ft-l2 holds the highest order gear-engaging arm in its rocked position in spite of the fact that arm d2 was disabled to release pin 44 and shaft i6 by the shiftl ing of cam shaft 3S. In the other eleven orders, these gear-engaging arms are rocked only by the single tooth S2 on the square root cams Sti-ill to Sti-l. However, the tooth S2 of the twelfth order cam StD-f2 will lie against the side of its associated gear-engaging arm 7u, preventing the cam shaft 38 from being transiated to the right into operative position, when the carriage is in the extreme right-hand position, unless shaft is roclced. Each gear-engaging arm 75) is provided at its upper edge with a tooth-shaped pressure face 7l (FlG. 7) adapted to be engaged by the tooth S2 of the associated square root cam 5ft-l2 to 5ft-ll. rfhe gear-engaging arm is also provided with a depending tail 73 which engages a stud 74 on the 1 to U5 selection bar 75 in the adjacent lower order of the selection mechanism. The degree of rocking of the gear-engaging arm 7@ is so compute that the rocking of the arms, by the associated square root cam, moves the l to 5 bar 75 of the next lower order to the 5 position. Normally, the gear-engaging arm 7u is urged to an inoperative position (counterclockwise in PEG. 7) by a torsion spring 80. It is thus obvious that as the cam shaft 38 is rotated (counterclockwise in FiG. 7) it successively brings its teeth 52 into rocking engagement with the respective gear-engaging arms 7d, Rocking of a gear-engaging arm is operative to insert a value of "5 into the to 5 selection bar 75 of the next lower order, and to move the coordinal feed gears 7S into mesh with the associated drive gear 79, as will be mentioned in the next subsection.

(3) Feed gears and drive (FIG. 7).-It is also necessary to drive the selection mechanism in a desired progression of single values beginning with the twelfth order of the selection mechanism and shifting order-by-order toward the right. For this purpose, I prefer to utilize, as i did in my former patent, No. 2,736,494, a plurality of feed gears 78, one for each order of the selection mechanism. These feed gears are slidably but nonrotatably mounted on a transversely extending square shaft and are operable to rotate a plurality of ordinally arranged selection drive gears 79. Each gear-engaging arm is also provided with an ear 72 adapted to engage a conically shaped hub 77 of the feed gear 73 and translates the feed gear to the left into mesh with the drive gear 79, upon rocking of the arm 7d. A compression spring 9i is associated with each gear, and normally urges the gear 7S to the right to its inoperative position. Thus, the rocking of an arm 7@ translates the respective feed gear 78 to the left against the bias of its spring 91, and in doing so, brings the gear 7d into mesh with the respective drive gear 79. Thereafter, the rotation of the shaft 9i), which rotates all gears '73, drives the proper ordinal drive gear 79.

The drive gear 79 is used to drive the selection mechanism of its order a single step beginning with l in the second cycle of operation in order to provide the progression required in the 5s method of square root extraction. Therefore, the feed gears 78 and the shaft 9i) are given a single step of movement for each cycle of operation, beginning with the second cycle in each ordinal position of the carriage. ln other words, no rotation of the shaft 9? is required for add-back, carriage shifting, and the first subtraction of The mechanism for thus driving the square shaft 9i) in single increments of motion is shown fully in my above-mentioned patent, and for the sake of brevity, will not be mentioned here, except to point out that the three-armed lever 1625 in PEG. 4t) of Patent No. 2,736,494 is effective to cause rotation of the square shaft 9i?. Thus, through the gear 79, first, the "l to "5 selection bar 75 and thereafter the 6 to 9 selection bar 76 will be fed one increment of movement for each increment of rotation of the shaft 90.

(d) Termination and Release The square root operation is terminated, either by operation of a division stop key or the attempted overshifting of the carriage beyond its extreme left-hand position. Upon termination of the square root operation, the square root cam shaft wiil be returned to the left, or its inoperative position. When the division operation terminates, the link 27 is pulled downwardly (by mechanism shown in FIG. 40 of Patent No. 2,736,494) and rocks the pusher arm Z2 downwardly, releasing the lever 25. The cam shaft 38 (FG. 1), under the force of its spring 39 (PEG. 2), is thereupon moved to the left to render the cams Sit-1 to @4t2 ineffective. The downward movement of the link 27 also disengages the feed mechanism, i.e., the feed gears 73 shown in FiG. 7, from further operation. Therefore, regardless of whether the extraction operation is terminated by operation of the conventional stop key, or by completing the extraction in the lowest, or extreme right-hand, order of the iachine, the square root shaft is unlatched by link 27 and returned to the left to its normal inoperative position.

Vmechanism explained in Section C hereinafter.

kengaging arms.

nl. EXTENDED SQUARE hoor MECHANISM (A) Additional Cams (FIGS. l and 8) K It was mentioned in the earlier part of this disclosure that a .primary object of the invention is to extend the number of orders from which the root of a radicand can be extracted in the commercial square root calculating machine, as disclosed in my patent, No. 2,736,494, without redesigning the machine or changing the timing thereof.

In order to accomplish the obiects of this invention, I prefer to lengthen the square foot shaft 33 and mount a pair of additional square root cams thereon for contro-lling the extraction of square root through two more vorders for the machine without changing the timing of the machine. In the preferred yform of the present invention the right-hand end portion of the square root cani shaft 38 is substantially square in cross-section (see FIGS. l, 7 and 8). It is on this square portion of the shaft that I slidably and nonrotatably mount two additional square root cams Sil-l and Sil-2 (FIG. l) for controlling the extraction of square root from the lowest, or first and second, orders kof the machine. As best kshown in FIG. 8, I prefer to mount the two cams 50-2 and Ell-1 on a common hub, or spool, S1, so that they Ican be operated in unison. All of the square root cams Sd-IZ to Sil-li are successively staggered at 36 on the cam shaft and, in accordance with the novel construction of the present invention, both cams Sil-i2 and dil-2 lie in the same angular position on the shaft, and cams Eil-lll and 5il-1 also lie in the same angular relationship to the sha-Et. Obviously, in my prior patent, the cams in the twelfth and second orders would be operative simultaneously, and likewise the cams in the eleventh and iirst orders. The presen-t mechanism is designed to avoid this `diiiculty, and thus enables the cams to operate sequentially, and without any duplicate operation, even though two pairs of cams occupy the same angular position. Y

y In the present machine I avoid the above-noted difyiiculty by shifting theV two additional square root cams Sil-2 and Sil-1 (rightward as seen in FIG. l) on the square root shaft 38 into operative position after the higher two orders of square root is extracted, by mechanism explained in the next section. By delaying the shifting of the two additional cams Sil-2 and tl-l into alignnient with their respective gear-engaging arms 7d, the tooth 52 of the highest two cams 50-12 and Stlll rocks the gear-engaging arm associated with these two orders before the additional cams become operative. Furthermore, before the two additional cams dll-2 and dil-1 become operative to rock their respective gear-engaging arms 7d, the highest two square root earns 5d-12 and ddii, and incidentally cams Sii-lil to 56-3, are shifted (lettward as seen in FIG. l) out of alignment with the gear-engaging arms .associated with these cams, by the By these means I am enabled to avoid operation of each angular-ly identical pair or" square root cams simultaneously.

Therefore, I provide a machine for extracting twelve orders of square root with the same machine timing as provided in the conventional ten-order square root machine.

The two additional square root camsti-Z and tl-l are shifted rightwardly on the square portion of shaft 3S after three orders of square root have been extracted; In this way the teeth 52 on the highest two camsk Sil-l2 vand Slilll have rocked their respective gear-engaging arms 7@ before the lowest 4two-order cams 50-2 and dii-il yare shifted into alignment with their respective geary Furthermore, before the two additional cams Sii-2 and .Sil-i become effective .to rock their respective gear-engaging arms 7h, the main portion of the squareroot cams dll-l2 to StB-3 is shifted out of alignment with the arms 7%. ln this way, I have provided l@ a machine for extracting twelve orders of square root with the san e machine timing as provided in the conventional ten-order square root machine.

(B) Control Slide for Additional Cams The two additional square root cams Sil-2 and Sil-i (which are preferably termed on the common hub, or sleeve, 5l) are shifted rightwardly on the square portion of the cam shaft 38 by means of a control slide lidi extending across `the rearward edge of the keyboard. The slide itil is sldably mounted on a pair of brackets ttifi by any suitable means, such as screws 104, threaded into the brackets and extending through slots 105 in the slide (see FIGS. 2 and 7), the brackets being aftixed to the square root control box indicated at 99 and fully shown and described in the above-noted patent. The control slide lill. is urged to the left by aspring 166 connected to vone of the screws ldd and a pin lil? aiiixed to the slide i191. Subsequent to rightward movement of the control slide lill and the two cams Sil-2 and Sil-2l against the tension of the spring M26, the slide and cam-s will be latched in operative position, by latch-ing means described hereinafter, until the square root operation is terminated As best seen in FIGS. l and 8, the two additional square root cams Sii-2 and Sil-1 are constructed with the comm-on hub 5i which is provided with a suit-able square aperture `for mating with the square portion of the shaft 3d and an annular groove ldd for controlling coaxial movement of the cams. Embraced within the groove ldd is a pin 1&2 aiiixed to, and extending downwardly from, an arm protruding rearwardly from the right-hand end of tle controi slide lill. The pin 102 rides within the groove ltlil at all times and thereby effects shifting of the extra square root cams Sti-2 and Sil-l whenever the slide itil is caused to shift from its inactive to its active control position, by means to be described next, Obviously ythis shitting could be done at any time after the completion of operation in the eleventh order and prior to initiation of operation in the second. It is more convenient, however, to shift these cams as the control mechanism has completed three ordinal series of operations, i.e., at the time cam shaft 38 rocks cam dil-9 to its eiiective position. As was mentioned under Section II, Subsection (b) (l) above, lever 25 and arm 3d are effective, upon initiation of the division operation, to move the cam shaft and cams Ell-12 to 5%-3 thereon into operative position for causing the square root extraction operation. However, in the preferred torni of the present machine the extra cams Sil-2 and 5tl-i are not moved rightwardly into operative position until three ordinal series of operations have been completed, i.e., until the earn shaft 38 has rotated at least 72. In order to shift the control slide to the right I provide the ninth order square root cam 59 (ie, the 4fourthcarn counting from left to right) with an ear liti extending rightwardly from the web of the cam Sil-9. Actuating ear dit? is provided with an inclined cam face which, during the third rotation of the cam shaft 33, engages la pin lll afiixed to, and extending downwardlyy from, a rearwardly projecting iinger of the control slide 'idf-l, thereby camming the slide ,r-igh-twardly. It will be recalled that the shaft T5S is shifted to 4the right, as viewed in iii-G. l, to place the square root cams 5th-i2 kto :d-3 in operative position. Rightward movement of the shaft brings the actuating ear lit) into the plane of pin About midway through the third increment of rotation of the square root cam shaft 38,

the cam face of ear il@ engages pin lll and forces the control slide lill toward the right. As was mentioned earlier, rightward movement of the control slide 101 shifts the two `additional cams Sil-2 and tl-l rightwardly on the square portion of shaft 3S. Thus, the additional square root cams dil-2, and Sti-1 are'moved into operative position after lthe first three cams, .Sil-12 59-11 and Sti-1h, have caused the extraction of the square root from the highest three orders of the accumulator.

It can be mentioned again that the actuating ear 11i) could have been constructed on the web of any of the square root cams, except cams Sti-12 or 5041, because the rotation of these two cams occurs too early in the square root operation for placing the additional cam in operative position. The use of cam Sti-3 would also be undesirable because its operation occurs too late in the machine operation to effectively place the additional cams in operative position. l chose to place the actuating ear llt) on the ninth order cam %-9 where it would cause the rightward movement of the control slide ltlt after the square root shaft 3S is rotated at least 72 and after the nighest three cams have tripped the gear-engaging arms 7h, as this location of the actuating cam works best with `a resetting device, which will be described hereinafter in Section (D). It will be recalled that the shaft 3? rotates one increment each time the carriage is shifted from one ordinal position to another but, unless the shaft 38 is moved to the right, the actuating ear 11d is not in the plane of the pin 111 and will bypass the pin. Hence, the control slide 101 is not moved in machine operations involving operations oher than square root. However, when the slide is adjusted during a square root operation, it will be latched in its adjusted position by mechanism now to be described.

in order that the spring 1% will not be effective to return the two lowest order cams Sti-2 and 5%-1 to their normal inoperative positions, l provide a means for latching the slide lill in its operative position until the square root operation is terminated. Afiixed to the ear 28 (FIG. 5 of the previously mentioned link 27 is a pin 115, best seen in FiGS. 3 and 4. Pin 11S normally lies slightly below a leaf spring 116 fastened by any suitable means, such as screws 117, to a leftwardly extending arm 11S of the control slide itil (see IGS. l and 4). It will be recalled that link 27 is urged upwardly upon initiation of the square root operation. Upward movement of the link 27 will cause the pin 115 to bend the leaf spring 116 upwardly, and the spring will remain deformed until the control slide 1F31 is shifted to the right by the actuating cam 11d, previously mentioned. Upon rightward movement of the slide lill, the leaf spring 11o is snapped back to its normal condition, whereupon the leftmost edge of the spring 116 will abut the pin 115 and latch the control slide lill in its rightward shifted position, against the urgency of its spring 1%. It will be recalled that when the square root operation is terminated, as explained in Section il, Subsection (d) above, the link 27 is pulled downwardly. Thus, the pin 115 is removed from engagement with the leaf spring 116 and the spring 1de will return the slide 191 and the two additional cams itl-2 and 5ft-1 to their vinoperative position.

(C) Cam Shaft Release Mechanism (FIGS. 1 and 5) In order to prevent simultaneous operation of the twelfth and second order cams, and also the eleventh and rst, it is not only necessary to shift cams 5h-1 and Sti-2 to their operative position after operation Iis completed in the eleventh order, it is also necessary to disable the twelfth and eleventh before operation can start in the second order. Again, means could be provided to disable cams dil-l1 and Sti-l2 at any time after operation is completed in the eleventh order. However, it is more simple and satisfactory to disable all the cams on shaft 3S, i.e., cams Sti-3 to 5ill2, inclusive, with one operation. have been extracted and the carriage starts its eleventh shift operation, i.e., from the third to the second coordinal position, the portion of the square root cams (5h-12 to 5&3-3) is released to return to their normal inactive position while the additional square root cams dil-2 and dil-lt remain in their operative position throughout the remaining two orders of square root operation.

Thus, after ten orders of square root.

When the carriage 56 shifts from its third to its second coordinal position (i.e., after ten ordinal series of square root operations), a roller 121 (FIG. 1) fastened to the front carriage rail 56 of the accumulator carriage contacts a cam surface 122 on the rearward edge of a cam shaft releasing slide 123. The slide 123 is slidably mounted on a bracket 124 extending rightwardly from the side frame of the machine, the slide 123 being mounted by any suitable means, such as a pair of pins 125' extending upwardly `from the bracket 124 into suitable slots 125 provided in the slide 123. in FIG. l the roller 121 is shown in the position that it will occupy during the tenth order of square root extraction. During the next, or eleventh, leftward shift of the carriage, the roller 121 forces the cam shaft releasing slide 123 forwardly against the tenison of a spring 127 connected between one of the pins 125 and a stud 128 fixed to the slide 123. Forward movement of the slide 123 is effective to cause the pusher arm 22 (FIG. 5) to release the square root cam shaft 38 (FG. l) for return to the left, or normal inactive position, under force of the coil spring sa (sro. 2).

Referring to FIGS. 3 and 5, the releasing slide 123 has a downwardly extending ear 29, which ear is provided with an inclined cam surface 13@ for engaging the pin 26. As best seen in FIG. 5, the forward movement of the slide 123 (to the left in this figure) causes the cam surface 13@ to engage the pin 26 and rock the pusher arm 22 downwardly (clockwise). The rocking of the pusher arm 22 releases the cam shaft shift lever 2S, whereupon the cam shaft 38, under the force of its spring 39, is moved to the left and renders the first series of cams Sti-12 to Edf-3 ineffective. After the pusher arm 22 is rocked, it will lie below the lever 25 and so it is ineffective to cause a second rightward shifting of the square root cam shaft 38 until another square root operation is initiated and the shaft Ztl is first rocked clockwise and then counter-clockwise, as was mentioned in Section II, Subsection (b) above. Thus, the rst series of square root cams dil-12 to 5ft-3 are shifted to their inoperative position after ten orders of square root have been extracted, while the additional, or second, series of cams 5ft-2 and Sti-1 remain in their operative position. These cams will remain in their operative position until the link 27 is pulled downwardly upon termination of the square root operation. lt should be mentioned here, that in the above-described preferred form of my invention, the square root cam shaft 33 is rotated a total of 396. Even though the cams are set at an angular distance of 36 apart (the spacing of the prior machine), there will be no simultaneous operation of, or interference between, the cams Sd-lZ and Sil-11 associated with the highest two orders of the machine and the cams Sd-Z and 543-1 associated with the lowest two orders of the machine to cause an extraction from two orders at the same time. After ten orders of square root have been extracted, the highest ten orders of square root cams are returned to their normal inactive position, while the other two square root cams `remain in their operative position until the square root operation is terminated. Upon termination of the operation, the square root cams Sil-2 and Stiel of the lowest two orders are returned to their inoperative position (by release of slide 101) where they will remain until they are again moved to the left by the actuating cam 11i).

(D) Auiomalz'c Resettl'ng of Cam Shaft (FIGS. 1 and 9) lf for any reason, the square root cam shaft 3S is blocked against rotation, the coupling slip clutch 5S will slip until the obstruction is removed. When this happens, the cam shaft will be out of time relative to the ordinal position of the carriage, because in square root extraction, the rotation of the cam shaft is dependent upon the orderby-order shifting of the carriage, as previously described. in the present machine provide means for automatically retiming the cam shaft 38 relative to Ithe carriage whenever the carriage is shifted to either of its extreme end positions. As previously mentioned, at the beginning of the square root operation, the carriage is shifted first to its extreme left-hand position, and the accumulator is cleared; and then the carriage is shifted to its extreme right-hand position before the actual extraction operation begins. Thus, I can provide a means, utilizing the ex* treme movement of the carri age, for retiming, Vor resetting, the square root cam shaft before the shaft is shifted into its operative position for controlling the extraction of square root.

Referring now to FiGS. l and 9, there is .shown a bracket 135 fastened to the auxiliary crossframe 47 of the machine by a screw 136. The bracket 135 extends forwardiy from the crossframe and partially surrounds the square rootcam shaft 3S adjacent the right side of the seventh order square root cam 50-7. Rockably and nonslidably mounted on the shaft 3S, next to the bracket 1255,v is a substantially U-shaped aligner 133 (FIG. 1). The aligner 138 includes left and right arms 139and 14h, respectively, depending from a narrow bar 141i. The left arm of the aligner 138 carries a short pin 142 (FiG. 9) extending to the left into an arcuate notch 137 provided in bracket 135. For purposes which will become apparent hereinafter, the prin 142 kand notch 137 prevent the aligner 138 from rotating through an angle greater than 72. Depending on the angular position 1of the -cam shaft 3B, the tooth 52 of the sixth order square root cam 5'0-6 will lie to either side of the bar, or bridge, 141 of the aligner 138, for causing limited rotation of the aligner.

FiG. 9 shows the aligner 138 and the sixth order cam Sii-6 in the position -they assume at the beginning of the extraction phase of the square root operation. After ten orders yof square troot extraction, and before the shift to the next ordinal position, thetooth 520i the cam Sti-6 has rotated 324 to a point where it is against the rearward side (left in FIG. 9) of the aligner 13S which has not yet been rotated. During the following two orders of square-:root extraction, the tooth 52 of cam 50-6 will force the aligner 138 to rotate through an angle of 72, moving the pin 142 from the position shown in FiG. 9 in-to'contact with the forward edge of the arcuate notch 137, thereby preventing any further rotation of the square root `cam shaft 3S (clockwise in FlG. 9). Conversely, upon rotation of the cam shaft 38 in the other direction (counter-clockwise in FiG. 9), the sixth orderfcarn 50-6 willrotate until the tooth 52 hits the bridge 141 of the rocked aligner 138. Further rotation of the cam shaft will return the aligner to the position shown in FIG. 9 whereupon the pin 142 once again abuts the rearward edge of the notch 137 and prevents further rotation of the shaft.

Suppose now that during leftward shift of the carriage, rotation of the square root cam shaft 38 is blocked after rotating 108, further leftward shifting of the carriage willcause the slip clutch S5 (FIG. 1) to slip and prevent damage to the machine. if, after the obstruction is removed, the carriage is shifted toward its extreme right- 'hand position, the camshaft is then rotated in the opposite direction the previously rotated 108, after which the aligner'itd stops further rotation of the shaft. As the carriage continues to `shift toward the right, the slip clutch 55 will'yield until the carriage is in its extreme nighthand position, thereby automatically retiming, `or resetting, the cam shaft kto the carriage `position for eifecting square root operations. After .the obstruction which blocked `rotationfof the cam shaft 38 is removed and the carriage is shifted to either of its extreme positions, the pin 142 will abut either edge of the arcuate notch 137 yto cause the slip clutch 55 to slip until the carriagereaches its extremeposition which, as can be seen, automatically retimes the lcamshaft relative to the carriage. Therefore, I provide a novel resetting device for the square root cam shaft which will automatically retime the shaft if, for

any reason, the shaft is blocked during a machine operation.

(E) Operation It is believed that the operation of my invention for extracting twelve orders of square root will be readily understood from the above description. However, it can be mentioned briefly that after the radicand is set into the accumulator and the carriage is in its extreme right-hand position, the pusher arm 22 (FTG. 5) wiil effect a right shift of the square root cam shaft, as explained in Section (b), Subsection (l) above, and the cam shaft will be latched for ten orders of square root extraction. After the root is extracted from the highest three orders of the machine, the rotation of the square root cam shaft causes the actuating gear 118 (FIG. l)

on square root cam Sti-9 to drive against the pine 111 (see Section IH, (B)) and shift the slide 101 to the right for bringing the additional square root cams 5ft-2 and Sti-1 (Section III, (A)) into operative alignment with 4their associated gear-engaging arms 7d (FIG. 7), for the remaining orders of square root extraction. It will be recalled that upon initiation of the square root operation, the upward movement of the link 27 causes the pin 115 thereon (FIGS. 1 and 5) to bend the leaf spring 116, on the ieft-hand portionof slide 161, whereby pin blocks return of the slide after it is shifted to the right. As the register carriage makes its tenth leftward shift, the roller 121 (FIG. 1) drives the cam shaft release Slide 123 (Section Hl, (C)) forward, which slide drives the pusher arm 22 downwardly for releasing the square root cam shaft 318 and the main portion of the square root cams Sti-12 to 50-3, which cams then return to their inactive position. However, the additional cams Sii-Z and 5ft-1 remain in the active position until the square root operation Vis terminated by an attempted over-shift of the carriage. The termination of a square root operation (Section (cl)) forces the link 27 and pin 115 to move downwardly and releasethe slide, as well as the additional cams Sii-Z and Sth-1. Thus, upon completion of the square root operation, all of the square root cams 504.2 to Sti-1 will have returned to their home position.

From the foregoing description of a preferred form of my invention, it is seen that i have provided a mechanism for solving the exasperating problem of building a twelveorder machine for extracting square root without completely redesigning the commercial macldne made in accordance with the teaching of United States iatent No, 2,73 6,494. With my invention, the square root cams me still spirally staggered at 36 on the camk shaft, but now the cam shaft is rotated 396 to cause extraction of square root Nfrom twelve orders of the machine. This is so because the lowest order cams are not shifted into operative position until the cam shaft has caused operation in the two highest orders at least, and preferably has rotated 72. Furthermore, the earns associated with the higher orders of the machine are out of operative position before the cams associated with the lowest orders of the machine become effective to cause the extraction of the Lroot yfrom these orders.

Although the present invention has been described with respect to a single embodiment, it will be appreciatedy by a mechanism for extending the number of orders in which square root can be extracted Without changing the timing of the machine comprising:

additional Cams slidably mounted spirally on said cam shaft for effecting the extraction of the root, and control means for slidably moving said additional cams relative to said cam shaft in timed relationship with the rotation of the shaft.

2. In a calculating machine for the extraction of square root having:

an ordinally arranged selection mechanism,

means for inserting a value of 5 in a preselected order of said selection mechanism,

setting means operable to progressively adjust said selection mechanism of the next higher order to said preselected order in increments corresponding to a value of 1,

ordinally operative adjusting means operable to adjust said setting means for operation in successive ordinal positions,

a cam shaft axially adjustable from an inactive to an \active position,

mechanism for axially adjusting said cam shaft in timed relationship with the operation of said machine, and

ordinally arranged cams mounted spirally on said cam shaft for operating said rst mentioned adjusting means in an ordinally diminishing sequence,

a mechanism for extending the number of orders from which the square root of the radicand can be extracted without changing the timing of the machine comprising:

a pair of cams each slidably mounted spirally on said cam shaft,

a means for shifting said pair of cams along said cam shaft from an inactive to an active position in timed relationship with the axial adjustment of said cam shaft, and

mechanism for effecting the return of said cam shaft to its inactive position prior to the termination of the square root extraction operation without effecting the position of said pair of cams whereby said pair of cams continue to operate said adjusting means in the aforementioned ordinally diminishing sequence.

3. The aperture of claim 2 comprising also a means for :latching said pair of cams in their actively adjusted position subsequent to the return of said cam shaft to its inactive position, and

means for releasing said latching means upon termination of the square root operation thereby returning the pair of cams to their inactive position.

4. ln a square root calculator having:

an ordinally arranged selection mechanism,

means for inserting a value of 5 in a preselected order of the selection mechanism,

setting means operable to progressively adjust the selection mechanism of the next higher order, in increments corresponding to a value of l,

ordinally operable adjusting means operable to adjust the inserting means and the setting means for operation in successive orders,

a cam shaft axially adjustable from its inactive to its active position for controlling operation of said adjusting means,

means operable for, rotating said cam shaft through a predetermined angular movement, and

a first series of ordinally arranged cams mounted spirally on said cam shaft for operating the adjusting CII means subsequent to positioning of said cams relative to the adjusting means in an ordinally diminishing sequence,

a mechanism for extending the number of orders from which the square root of a number can be extracted Without changing the timing of the machine comprising:

a second series of ordinally arranged cams slidably mounted spirally on said cam shaft at the end thereof for operating said adjusting means subsequent to positioning of these second series of cams relative to the adjusting means.

means for sliding said second series of cams along said cam shaft from an inactive to an active position in timed relationship with the rotational adjustment of said cam shaft,

said last mentioned means including a means effective after at least '72 rotation of said cam shaft for operating said sliding means, and

mechanism for effecting the return of said cam shaft to its inactive position after ten orders of square root have been extracted without altering the position of said second series of cams.

5. ln a machine for extracting the root of a number having:

an ordinally arranged selection mechanism,

setting means operable to progressively adjust each order of the selection mechanism in increments corresponding to 1,

means fon inserting a value of 5 in each order of said selection mechanism,

means for adjusting said inserting means in one order and operating said setting means in the next higher order,

a cam shaft,

means for rotating said cam shaft through a predetermined angular movement, and

ordinally arranged cams mounted spirally on the said cam shaft for operating said adjusting means in an ordinally diminishing sequence,

a mechanism for extending the number of orders from which a root of a number can be extracted without changing the timing of the machine comprising:

additional cams slidably mounted spirally on said cam shaft for effecting the extraction of the root in additional orders,

control means for slidably moving said additional cams relative to said cam shaft in timed relationship with the rotation of the shaft, and

a cam shaft resetting means for automatically retiming said cam shaft upon initiation of a machine operation.

6. A cyclically operable square root calculating machine comprising the combination of an ordinally arranged selection means,

a feed shaft rotatable through a predetermined angular movement with each cycle of machine operation,

a pluraiity of ordinally arranged connecting means positionable to operatively connect said feed shaft to an ordinally associated selection means,

means for sequentially positioning said connecting means in connecting position, said last-mentioned means including a cam shaft,

mechanism operable for rotating said cam shaft through an intermittent angular movement,

a first series of ordinally arranged cams mounted spirally on said cam shaft,

a second series of ordinally arranged cams slidably and nonrotatably mounted spirally on said cam shaft,

and cam followers for said first series and said second series of cams operative to position said ordinally associated connecting means in connecting position,

means for sliding said second series of cams axially of said cam shaft in timed relationship to the angular rotation thereof, and

means operated by said cam follower for inserting a value of 5 in the next lower order selection means.

7. The apparatus of claim 6 comprising also a means for axially moving said cam shaft from an active to an inactive position prior to operation of said second series of cams,

and a latch means for said second series of cams to retain said cams in their active position after, return of said cam shaft to its inactive position.

References Cited in the iile of this patent UNITED STATES PATENTS Ellerbeck Nov. 6, 1962 UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTIGN Patent Ne. 3,159,341 Deeember 1, 1964 i Grant C., Ellerbeck It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 5, 1ine Z3, before "and" insert an opening parenthesis; column 7, 1ine 6, for "5." read 5). 4; column 9, 1ine 12, for "foot" read root 1ine 16, Jfor "for" read of Column 11, 1ine 25, for "eher" read other Column 12, 1ine 16, for "tenison" read tension Co1umn 14, 1ine 17, for "pine" read pin Column 15, 1ine 52, Jfor "aperture" read apparatus Column 16, 1ine 12, for "means.," read means,

Signed and sealed this 27th day of July 1965.

(SEAL) Attest:

ERNEST W. SWIDERl I EDWARD J. BRENNER Attesting Officer Commissioner of Patents UNITED STATES PATENT OFFICE CERTIFICATE 0E CORRECTION Patent No 3,159 ,341 December 1, 1964 l Grant C. Ellerbeck 1t is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 5, line 23, before "and" insert an opening parenthesis; column 7, line 6, for "5." read 5). column 9, line 12, for "foot" read root line 16, for "for" read of column 11, line 25, for "oher" read other column 12, line 16, Jror "tenison" read tension Column 14, line 17, Jfor "pine" read pin column 15, line 52, for

"aperture" read apparatus Column 16, line 12, for "means," read means,

Signed and sealed this 27th day of July 1965. (SEAL) Attest:

ERNEST W. SWIDERV EDWARD J. BRENNER Commissioner of Patents Attesting fficer 

1. IN A CALCULATING MACHINE FOR THE EXTRACTION OF SQUARE ROOT HAVING: AN ORDINALLY ARRANGED SELECTION MECHANISM, ADJUSTING MEANS OPERABLE TO PROGRESSIVELY ADJUST EACH ORDER OF THE SELECTION MECHANISM IN INCREMENTS CORRESPONDING TO A "1", SETTING MEANS FOR INSERTING A VALUE OF "5" IN EACH ORDER OF SAID SELECTION MECHANISM, MEANS FOR OPERATING SAID SETTING MEANS IN ONE ORDER AND OPERATING THE SAID ADJUSTING MEANS IN THE NEXT HIGHER ORDER, A CAM SHAFT, MEANS FOR ROTATING SAID CAM SHAFT, AND ORDINALLY ARRANGED CAMS MOUNTED SPIRALLY ON SAID CAM SHAFT FOR OPERATING SAID OPERATING MEANS IN AN ORDINALLY DIMINISHING SEQUENCE, A MECHANISM FOR EXTENDING THE NUMBER OF ORDERS IN WHICH SQUARE ROOT CAN BE EXTRACTED WITHOUT CHANGING THE TIMING OF THE MACHINE COMPRISING: ADDITIONAL CAMS SLIDABLY MOUNTED SPIRALLY ON SAID CAM SHAFT FOR EFFECTING THE EXTRACTION OF THE ROOT, AND CONTROL MEANS FOR SLIDABLY MOVING SAID ADDITIONAL CAMS RELATIVE TO SAID CAM SHAFT IN TIMED RELATIONSHIP WITH THE ROTATION OF THE SHAFT. 